Comparative Phytochemical Insights and Potential Bioactivities of Phyllodium pulchellum Leaf and Bract Extracts

Phyllodium pulchellum (L.) Desv., a little-explored medicinal plant of the family Papilionoideae, is a deciduous woody shrub with large circular bifoliolate and persistent leafy bracts. The present investigation compares the phytochemical profile of methanolic extracts of P. pulchellum leaf (PPL) and green leafy bract (P. pulchellum bract [PPB]) using HRLCMS and their antioxidant and antimicrobial activities. Interestingly, PPB extract revealed higher contents of phenol and flavonoids and behaved as a potent free radical scavenger in both DPPH (IC₅₀ = 15.96 ± 0.67 µg/mL) and ABTS (IC₅₀ = 56.18 ± 1.7 µg/mL) assays. Furthermore, PPB shows a prominent antimicrobial impact on four different human pathogenic bacterial strains. From in silico investigation, it is evident that the methanolic extracts of PPB and PPL have a positive correlation with antibacterial activity. Methanolic PPL and PPB extracts yielded 55 chemical components, including many novel and unidentified phytocompounds. Molecular docking approach is adopted to examine the antibacterial qualities of isolated phytometabolites, which offers untapped therapeutic potential of these compounds.